An electrical generator can be driven by a drive shaft having uneven speed or torque which can result in unwanted oscillation or a mechanical shearing of the drive shaft. For example, an aircraft can provide rotation to the drive shaft from a prime mover such as a gas turbine engine. It is known to use a mechanical damper interposed in the drive shaft to reduce torsional oscillation of the drive shaft. But in applications where parameters of weight or volume are important such as in aircraft, a mechanical damper consumes valuable space and adds weight. Moreover a mechanical damper may not dynamically adjust to varying torque conditions. It is also known to provide an electrical damper that absorbs ripple in the mechanical torque by varying the size of the electrical load on the damper. However, the electrical load on the generator may be a constant power load that responds to changes in generator voltage by absorbing no more or less power as the voltage varies. So it is known to use a capacitor to filter a rectified output of the generator that may reactively absorb fluctuations in the electrical load which are out of phase with the ripple in mechanical torque. Yet there remains some power loss in such systems.